KDXRIDER.NET

will a bad crank seal prevent my bike from starting if it has everything it needs to run?

not likely, though it may run roughly.

would it b my exaust valve stuck open?

Again, not likely. A stuck KIPS valve won't keep it from running, just from running well. Are you 100% sure you have everything it needs to run? These bikes are extremely simple...fuel, spark, compression and they will start.
FUEL/AIR

• First make sure that everything is mechanically sound.
• Pull the carb and disassemble and clean it (don't dip it).
• Make sure there are no holes/tears in the reed block, carb boots, airbox boot, filter.
• Make sure the reeds are good.
• Clean filter fresh mixed fuel.
• Repack silencer/drain OEM silencer
• Make sure all exhaust connections are god (head, pipe to silencer) and no holes
• Make sure the tank petcock is in good condition, screen not clogged.

SPARK

• New plug
• Make sure you have good spark
• Make sure all electrical connectors are clean and well seated
• Especially make sure your ground connections are good.

COMPRESSION

• Make sure compression is good
• Compression check
• Better yet leakdown test
• wouldn't hurt to pull the cylinder and visually inspect the top end, piston, rod, bearing play, port conditions

If you do all that and it doesn't run then you are likely working on a Honda

Everythings in check all but the piston is loose when it connects to the rod but idk if that's supposed to do that

you know, I hate to be "that guy" but you have 3 different threads on the same topic and all of them in the wrong section

if you ask Jason to pool them all together into one thread in the right section we might get a much better picture of what is going on


now, when the piston is "loose" are talking side to side play, upside down or a wobble ?

start loading up some pictures

and while you are in there, buy yourself a wiseco piston because the stock 220 units are known to explode anyway
(pretty sure someone mentioned that in your first query)

yeah about the piston skirt an yeah it has the side to side play but I think that's normal

also when I took the header off the bike I stuck my finger in the port an right above where the header goes theres a piece of metal that I can tap with my finger and it rattles

congratulations, you found the main KIPS valve
perfectly normal

so you ran her without any coolant, the piston is intact, compression is good, you have spark, you have fuel
there is no up-down play on the piston and no scoring on the inside of the cylinder ?

im guessing you fried the top end, have a shop check to see if the bore is still true and if it is run a scotchbrite pad with some WD-40 through there, install a new wiseco piston and you are good to go

in the mean time, watch this video of me frying my top end
a coolant hose had come loose and it might sound familiar to you

[youtube][/youtube]

no sir it doenst sound anything like that it was running like it has been for 2 months then as soon I clicked to forth I pinned it an that's when the rattling started an it just slowly gave away an never started back